1. Field of the Invention
The present invention relates to a method for operating a position measuring system, as well as to a position measuring system suitable for this.
2. Description of the Related Art
Known position measuring systems are customarily supplied with a defined operating voltage by the downstream-connected evaluating unit, or control unit, via a connecting cable. The operating or supply voltage must be within predefined tolerance limits for maintaining the correct operation of the position measuring system. As a rule, a defined voltage drop occurs along the connecting cable. So that the voltage drop becomes as small as possible, it is necessary to keep the electrical current consumption, or the power loss, of the position measuring system low. For assuring this it is known to operate the light source of the position measuring system, one of the largest power consumers in the system, not continuously, but in a pulsed manner. In this connection, reference is made, for example, to U.S. Pat. No. 4,079,251, the entire contents of which is incorporated herein by reference; the pulsed light source operation in a battery-buffered incremental position measuring system is disclosed in it. The pulse frequency of the light source, or the clock rate, between the individual light pulses in the proposed system is selected on the basis of an estimate of the maximum output frequency of the generated incremental signals of the position measuring system.